Reef
down to 30 m
Turtle Rock
Easy 10-15 m dive in Donald Duck Bay, Island 8, with mild current, turtles and Kuhl's stingrays; great for night diving, especially for beginners.
- Open Water
- Leopard (zebra) sharks
Similan Islands & Khao Lak
Diving in Thailand
20 documented dive sites, 6 of them for Open Water divers. Known for manta rays, leopard (zebra) sharks and whitetip reef sharks.
- Best months
- Feb–Apr
- Water
- 26–29 °C
- Levels
- Open Water, Advanced, Experienced
- Diving from
- Liveaboards, Day boats
- Nearest airport
- HKT
When to go
Pick a month: the diving season, from published sources, and the typical weather.
Pick a month
- Best
- Good
- Possible
- Closed
- Not documented yet
Similan Islands & Khao Lak in October
Possible- Sea
- 29 °C
- at the surface
- Air
- 29 °C
- 26 °C at night
- Rain
- 320 mm
- one of the wettest months
- Wind
- 15 km/h
- on average
The coolest water of the year.
Typical weather, not a forecast: averages for 2021–2025 (air, rain, wind) and 2023–2025 (sea), data from Open-Meteo (ERA5 / Copernicus, Météo-France). Covers an area of roughly 10 to 25 km around the destination.
National park open 15 Oct – 15 May, closed during the SW monsoon. Currents and big pelagics increase from late February.
Usually closed or not dived: Jun–Sep.
Dive sites in Similan Islands & Khao Lak
From the easiest to the most demanding. Levels with a dashed outline are estimates we are still verifying.
Open Water friendly
usual dive down to 18 m6 sitesReef
down to 40 m
Anita's Reef
Gentle sandy slope with coral bommies, garden eels and Kuhl's stingrays, an ideal check-out dive on a Similan liveaboard.
- Open Water
- Turtles
Reef
down to 40 m
Waterfall Bay
- Open Water
- Nurse sharks
For Advanced divers
usual dive down to 30 m13 sites
Richelieu Rock
Schools of chevron barracuda overhead while tigertail seahorses, harlequin shrimps and ghost pipefish hide in fields of soft coral.
- Advanced
- Wall
- Whale sharks
Pinnacle
down to 40 m
Koh Tachai Pinnacle
A hard-coral-topped pinnacle from 12 m where mantas cruise and batfish hang in the current, reached only by liveaboard.
- Advanced
- Manta rays
Reef
down to 30 m
Breakfast Bend
Healthy hard coral and abundant fish life, where leopard sharks are common on the reef.
- Advanced
- Leopard (zebra) sharks
Rock formations
down to 35 m
Christmas Point
Boulders, soft corals, arches and passages spread over a huge area, with whitetip sharks often seen in the deeper sand.
- Advanced
- Whitetip reef sharks
Reef
down to 26 m
Honeymoon Bay
Sheltered hard-coral bay used for moorings and night dives, when crabs, lobsters, cuttlefish and nurse sharks come out.
- Advanced
- Nurse sharks
Reef
down to 40 m
Koh Bon West Ridge
A soft-coral ridge off Koh Bon's west side dropping to 35-40 m, called maybe the best place to find manta rays in the region.
- Advanced
- Manta rays
Wreck
down to 22 m
Premchai Wreck
Upturned tin dredger 40 minutes from Thap Lamu pier, coated in clams and hard corals, with honeycomb morays and batfish.
- Advanced
- Barracuda
Wreck
down to 20 m
Boonsung Wreck
- Advanced
- Schooling pelagics
Rock formations
down to 40 m
Deep Six
- Advanced
- Schooling pelagics
Rock formations
down to 35 m
North Point Similan
- Advanced
- Schooling pelagics
Wreck
down to 35 m
Seachart Wreck
- Advanced
For experienced divers
usual dive down to 40 m1 siteMarine life
When the big encounters happen, month by month.
| Species | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Manta raysSource: divessi.com | ||||||||||||
| Whale sharksSource: divessi.com |
- Peak season
- Seen
Manta rays: Feb–Apr. Whale sharks: Feb–Apr
Also reported here, season not documented yet:
- Leopard (zebra) sharks
- Whitetip reef sharks
- Turtles
- Guitarfish
- Stingrays
- Tuna
- Barracuda
- Trevally
- Cuttlefish
- Frogfish
- Ghost pipefish
- Harlequin shrimp
- Nudibranchs
- Octopus
- Seahorses
- Batfish
- Moray eels
- Snappers
- Bumphead parrotfish
- Napoleon wrasse
- Sea snakes
Where is the Similan Islands & Khao Lak?
- Nearest airport
- HKT
- How people dive here
- Liveaboards, Day boats
Similan Islands & Khao Lak: frequently asked questions
- When is the best time to dive Similan Islands & Khao Lak?
- The best months to dive Similan Islands & Khao Lak are Feb–Apr. Diving usually stops in Jun–Sep. National park open 15 Oct – 15 May, closed during the SW monsoon. Currents and big pelagics increase from late February.
- Is Similan Islands & Khao Lak good for beginner divers?
- Yes, partly: 6 of the 20 dive sites we document are suited to Open Water divers, including Turtle Rock, Anita's Reef and Waterfall Bay. The others need more experience or a higher certification.
- What is the water temperature in Similan Islands & Khao Lak?
- The water is usually between 26 °C and 29 °C over the year.
- What marine life can you see in Similan Islands & Khao Lak?
- Divers regularly see manta rays (Feb–Apr), leopard (zebra) sharks, whitetip reef sharks, turtles, guitarfish and stingrays.
- How do you dive Similan Islands & Khao Lak?
- The nearest airport is HKT. Ways to dive here: liveaboards and day boats.
About this page
Seasons and marine life come from the sources below. Site levels and depths marked as estimated come from our original catalogue and are being checked one by one. Conditions change: always confirm with a local dive centre.
Your next dive is somewhere out there.
Find my next dive tripPhoto credits
- Granite boulders and clear water, Similan Islands, KOSIN SUKHUM, CC BY-SA 4.0, via Wikimedia Commons
- Richelieu Rock dive site, Similan / Surin, Mr.CMBurns, CC BY-SA 4.0, via Wikimedia Commons
- Sunlight and bubbles in deep blue water, Sarah Lee, Unsplash License, on Unsplash
